Why Are People Reluctant to Exchange Lottery Tickets?

Students were given lottery tickets and then were asked to exchange their ticket for another one, plus a small monetary incentive. Less than 50% agreed. In contrast, when given pens, and the same exchange offer, over 90% agreed. Experimental control rules out that the reluctance to exchange lottery tickets results (a) from overestimation of the winning probability of one's own ticket; (b) from a concern that the ticket, once exchanged, might win in the hands of another; (c) from an overly low transaction cost; (d) from "paranoia" due to the bizzarreness of the social situation we created; (e) from "bonding" to the ticket. Rather, the possibility for ex post regret that exists when exchanging lottery tickets, but not pens, underlies this reluctance. The notion of regret is broader than previously supposed.